Wikipedia Content is not displaying

Had the same problem. You need to make the following change to the functions.php file.

edit the file and go to line 195

/wp-contents/plugins/wp-wikibox/includes/functions.php

Change the following to add the Expect clause. You will need to change the previous line too:

curl_setopt( $curl, CURLOPT_HTTPHEADER, array( "Cache-Control: max-age=0",
															 "Connection: keep-alive",
															 "Keep-Alive: 300",
															 "Accept-Charset: ISO-8859-1,utf-8",
															 "Accept-Language: $wikibox_options[language]",
															 "Pragma: ",
															 "Expect:" ) );

Once I had made that change the box started to populate again.